[Short-term effects of fine particulate matter exposure on pulmonary function in healthy young adults: a time series study]

Objective: To explore the short-term effects of fine particulate matter (PM2.5) exposure on pulmonary function of healthy young adults in Beijing. Methods: In this time series study, twenty-four healthy young adults who living around Guanyuan area were investigated in Beijing. The follow-up study was lasted for 12 days in total from Nov. 28, 2016 to Dec. 9, 2016, and pulmonary spirometry and inpulse oscillometry parameters were measured daily. Air pollution data (including PM2.5, etc.) and meteorological data (temperature, humidity, etc.) were monitored based on Guanyuan monitoring site. The short-term effects of PM2.5 on pulmonary ventilation function and airway resistance of healthy young adults were analyzed by using generalized estimating equation (GEE). Results: In our study period, average daily concentration of PM2.5 were 100.7 μg/m(3). The single pollutant model showed that there were negative dose-response associations between PM2.5 concentration and forced vital capacity (FVC) and forced expiratory volume in one second (FEV(1)); and there were negatively correlated with daily mean level of PM2.5 lagged 0-1 days, and the strongest negative effect was in lag0. At lag0 day, each 10 μg/m(3) increase in PM2.5 concentration was associated with a significant decrease in FVC of 12.186 (95% CI: -15.573, -8.799) ml and in FEV(1) of 9.449 (95% CI: -13.265, -5.634) ml. Moreover, there were positive dose-response associations between PM2.5 concentration at lag0 to lag2 and peripheral resistance (Rp) , resonance frequency (Fres) and the fall in resistance between resistance at 5 Hz (R5) and resistance at 20 Hz (R20) (R(5-20)). And the strongest negative effect was in lag0. Each 10 μg/m(3) increase in PM2.5 concentration was associated with a significant increase in Rp of 2.444 (95% CI: 0.889, 3.999) Pa·L(-1)·s(-1) , Fres of 0.125 (95% CI: 0.082, 0.168) Hz and R(5-20) of 1.074 (95% CI: 0.444, 1.703) Pa·L(-1)·s(-1) at lag0 day. Conclusion: Short-term PM2.5 exposure has a negative and lagged effect on pulmonary function in healthy young adults.